It is enough to protect accesses to reject field of urb
by marking it as atomic_t,also it is the only reason of
existence of usb_reject_lock,so remove the lock to make
code more clean.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1177) modifies the USB core suspend and resume
routines. The resume functions now will take a pm_message_t argument,
so they will know what sort of resume is occurring. The new argument
is also passed to the port suspend/resume and bus suspend/resume
routines (although they don't use it for anything but debugging).
In addition, special pm_message_t values are used for user-initiated,
device-initiated (i.e., remote wakeup), and automatic suspend/resume.
By testing these values, drivers can tell whether or not a particular
suspend was an autosuspend. Unfortunately, they can't do the same for
resumes -- not until the pm_message_t argument is also passed to the
drivers' resume methods. That will require a bigger change.
IMO, the whole Power Management framework should have been set up this
way in the first place.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
usbmon can only be built as a module if usbcore is a module too. Trivial
changes to the relevant Kconfig and Makefile (and a few trivial changes
elsewhere) allow usbmon to be built as a module even if usbcore is
builtin.
This is verified to work in all 9 permutations (3 correctly prohibited
by Kconfig, 6 build a suitable result).
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1151) protects usbcore against drivers that try to
unlink an URB after the URB's device or bus have been removed. The
core does not currently check for this, and certain drivers can cause
a crash if they are running while an HCD is unloaded.
Certainly it would be best to fix the guilty drivers. But a little
defensive programming doesn't hurt, especially since it appears that
quite a few drivers need to be fixed.
The patch prevents the problem by grabbing a reference to the device
while an unlink is in progress and using a new spinlock to synchronize
unlinks with device removal. (There's no need to acquire a reference
to the bus as well, since the device structure itself keeps a
reference to the bus.) In addition, the kerneldoc is updated to
indicate that URBs should not be unlinked after the disconnect method
returns.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1139) adds a warning to the system log whenever ehci-hcd
is loaded after ohci-hcd or uhci-hcd. Nowadays most distributions are
pretty good about not doing this; maybe the warning will help convince
anyone still doing it wrong.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org> [2.6.27]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit de85422b94, 'USB: fix interrupt
disabling for HCDs with shared interrupt handlers' changed usb_add_hcd()
to strip IRQF_DISABLED from irqflags prior to calling request_irq()
with the justification that such a removal was necessary for shared
interrupts to work properly. Unfortunately, the change in that commit
unconditionally removes the IRQF_DISABLED flag, causing problems on
platforms that don't use a shared interrupt but require IRQF_DISABLED.
This change adds a check for IRQF_SHARED prior to removing the
IRQF_DISABLED flag.
Fixes the PS3 system startup hang reported with recent Fedora and
OpenSUSE kernels.
Note that this problem is hidden when CONFIG_LOCKDEP=y (ps3_defconfig),
as local_irq_enable_in_hardirq() is defined as a null statement for
that config.
CC: stable <stable@kernel.org>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Stefan Becker <Stefan.Becker@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1069c) changes the way OHCI root-hub status-change
interrupts are enabled. Currently a special HCD method,
hub_irq_enable(), is called when the hub driver is finished using a
root hub. This approach turns out to be subject to races, resulting
in unnecessary polling.
The patch does away with the method entirely. Instead, the driver
automatically enables the RHSC interrupt when no more status changes
are present. This scheme is safe with controllers using
level-triggered semantics for their interrupt flags.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The bus_id field is going away, use the dev_name() function instead.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This changes usb_create_hcd() to be able to handle the fact that
pci_name() has changed to a constant string.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit e872154921.
Andrey Borzenkov reports that it resulted in a totally hung machine for
him when loading the OHCI driver. Extensive netconsole capture with
SysRq output shows that modprobe gets stuck in ohci_hub_status_data()
when probing and enabling the OHCI controller, see for example
http://lkml.org/lkml/2008/7/5/236
for an analysis.
The problem appears to be an interrupt flood triggered by the commit
that gets reverted, and Andrey confirmed that the revert makes things
work for him again.
Reported-and-tested-by: Andrey Borzenkov <arvidjaar@mail.ru>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
USB: fix interrupt disabling for HCDs with shared interrupt handlers
As has been discussed several times on LKML, IRQF_SHARED | IRQF_DISABLED
doesn't work reliably, i.e. a shared interrupt handler CAN'T be certain to
be called with interrupts disabled. Most USB HCD handlers use IRQF_DISABLED
and therefore havoc can break out if they share their interrupt with a
handler that doesn't use it.
On my test machine the yenta_socket interrupt handler (no IRQF_DISABLED)
was registered before ehci_hcd and one uhci_hcd instance. Therefore all
usb_hcd_irq() invocations for ehci_hcd and for one uhci_hcd instance
happened with interrupts enabled. That led to random lockups as USB core
HCD functions that acquire the same spinlock could be called twice
from interrupt handlers.
This patch updates usb_hcd_irq() to always disable/restore interrupts.
usb_add_hcd() will silently remove any IRQF_DISABLED requested from HCD code.
Signed-off-by: Stefan Becker <stefan.becker@nokia.com>
Cc: stable <stable@kernel.org>
Acked-by: David Brownell <david-b@pacbell.net>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.
This patch fixes the problem by using the new function,
device_create_drvdata().
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1069b) changes the way OHCI root-hub status-change
interrupts are enabled. Currently a special HCD method,
hub_irq_enable(), is called when the hub driver is finished using a
root hub. This approach turns out to be subject to races, resulting
in unnecessary polling.
The patch does away with the method entirely. Instead, the driver
automatically enables the RHSC interrupt when no more status changes
are present. This scheme is safe with controllers using
level-triggered semantics for their interrupt flags.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Currently EHCI root hubs enumerate with a bDeviceProtocol code
indicating that they possess a Transaction Translator. However the
vast majority of controllers do not; they rely on a companion
controller to handle full- and low-speed communications. This patch
(as1064) changes the root-hub device descriptor to match the actual
situation.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Remove useless @type note for rh_string() and @r note for usb_hcd_irq()
since this two parameters were removed.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Over two years ago, the Linux USB developers stated that they believed
there was no way to create a USB kernel driver that was not under the
GPL. This patch moves the USB apis to enforce that decision.
There are no known closed source USB drivers in the wild, so this patch
should cause no problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Turns out that a company is out there using the vendor id of 0x0000 in
the wild, so use a real vendor/product id for the root hubs.
Now that the Linux Foundation has a real vendor id, we use that, and the
first product id:
0x1d6b is the vendor id of the Linux Foundation
0x0001 is the product id for Linux 1.1 root hubs
0x0002 is the product id for Linux 2.0 root hubs
The usb.ids file has already been updated with these values.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
usb: dma bounce buffer support V4
This patch adds dma bounce buffer support to the usb core. These buffers
can be enabled with the HCD_LOCAL_MEM flag, and they make sure that all data
passed to the host controller is allocated using dma_alloc_coherent().
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Convert from class_device to device for drivers/usb/core.
Signed-off-by: Tony Jones <tonyj@suse.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Arnd Bergmann wrote:
usb_hcd_flush_endpoint() has a retry loop that starts with a spin_lock_irq(),
but only gives up the spinlock, not the irq_disable before jumping to the
rescan label.
Alan Stern:
I agree with your sentiment, but it would be better to solve this
problem without using local_irq_disable().
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Not architecture specific code should not #include <asm/scatterlist.h>.
This patch therefore either replaces them with
#include <linux/scatterlist.h> or simply removes them if they were
unused.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
powertop currently tracks interrupts generated by uhci, ehci, and ohci,
but it has no way of telling which USB device to blame USB bus activity on.
This patch exports the number of URBs that are submitted for a given device.
Cat the file 'urbnum' in /sys/bus/usb/devices/.../
Signed-off-by: Sarah Sharp <sarah.a.sharp@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as989) makes usbcore flush all outstanding URBs for each
device as the device is suspended. This will be true even when
CONFIG_USB_SUSPEND is not enabled.
In addition, an extra can_submit flag is added to the usb_device
structure. That flag will be turned off whenever a suspend request
has been received for the device, even if the device isn't actually
suspended because CONFIG_USB_SUSPEND isn't set.
It's no longer necessary to check for the device state being equal to
USB_STATE_SUSPENDED during URB submission; that check can be replaced
by a check of the can_submit flag. This also permits us to remove
some questionable references to the deprecated power.power_state field.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as988) breaks usb_hcd_endpoint_disable() apart into two
routines. The first, usb_hcd_flush_endpoint() does the -ESHUTDOWN
unlinking of all URBs in the endpoint's queue and waits for them to
complete. The second, usb_hcd_disable_endpoint() -- renamed for
better grammatical style -- merely calls the HCD's endpoint_disable
method. The changeover is easy because the routine currently has only
one caller.
This separation of function will be exploited in the following patch:
When a device is suspended, the core will be able to cancel all
outstanding URBs for that device while leaving the HCD's
endpoint-related data structures intact for later.
As an added benefit, HCDs no longer need to check for existing URBs in
their endpoint_disable methods. It is now guaranteed that there will
be none.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as979) removes the last vestiges of urb->status from the
host controller drivers and the root-hub emulator. Now the field
doesn't get set until just before the URB's completion routine is
called.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
CC: Olav Kongas <ok@artecdesign.ee>
CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
CC: Tony Olech <tony.olech@elandigitalsystems.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as978) reorganizes the way usbmon uses urb->status. It
now accepts the status value as an argument.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as971) fixes a small mistake: The URB's completion status
needs to be adjusted before the URB is passed to usmon_urb_complete(),
not afterward.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as970) adds a new urb->unlinked field, which is used to
store the status of unlinked URBs since we can't use urb->status for
that purpose any more. To help simplify the HCDs, usbcore will check
urb->unlinked before calling the completion handler; if the value is
set it will automatically override the status reported by the HCD.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
CC: Olav Kongas <ok@artecdesign.ee>
CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
CC: Tony Olech <tony.olech@elandigitalsystems.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as969) continues the ongoing changes to the way HCDs
report URB statuses. The programming interface has been simplified by
making usbcore responsible for clearing urb->hcpriv and for setting
-EREMOTEIO status when an URB with the URB_SHORT_NOT_OK flag ends up
as a short transfer.
By moving the work out of the HCDs, this removes a fair amount of
repeated code.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
CC: Olav Kongas <ok@artecdesign.ee>
CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
CC: Tony Olech <tony.olech@elandigitalsystems.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as954) implements a suggestion of David Brownell's. Now
the host controller drivers are responsible for linking and unlinking
URBs to/from their endpoint queues. This eliminates the possiblity of
strange situations where usbcore thinks an URB is linked but the HCD
thinks it isn't. It also means HCDs no longer have to check for URBs
being dequeued before they were fully enqueued.
In addition to the core changes, this requires changing every host
controller driver and the root-hub URB handler. For the most part the
required changes are fairly small; drivers have to call
usb_hcd_link_urb_to_ep() in their urb_enqueue method,
usb_hcd_check_unlink_urb() in their urb_dequeue method, and
usb_hcd_unlink_urb_from_ep() before giving URBs back. A few HCDs make
matters more complicated by the way they split up the flow of control.
In addition some method interfaces get changed. The endpoint argument
for urb_enqueue is now redundant so it is removed. The unlink status
is required by usb_hcd_check_unlink_urb(), so it has been added to
urb_dequeue.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
CC: Olav Kongas <ok@artecdesign.ee>
CC: Tony Olech <tony.olech@elandigitalsystems.com>
CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This path cleans the exit paths of usb_register_bus() [to use a goto
schema], maximum line length (keeping it under ~75).
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This introduces /sys/bus/devices/usb*/authorized_default; it dictates
what is going to be the default authorization state for devices
connected to the host. User space can set that using the sysfs file.
We hook to the root hub instead of to the device controller as it is
quite easy to get to it in sysfs from the device structure (device
5-4.3 is usb5) vs. backtracking to the controller device.
By default it is set to be 'authorized' (!0) for normal, wired USB
devices and 'unauthorized' (0) for Wireless USB devices.
As suggested by Adrian Bunk, make authorized_default static
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as953) separates out three key portions from
usb_hcd_submit_urb(), usb_hcd_unlink_urb(), and usb_hcd_giveback_urb()
and puts them in separate functions of their own. In the next patch,
these functions will be called directly by host controller drivers
while holding their private spinlocks, which will remove the
possibility of some unpleasant races.
The code responsible for mapping and unmapping DMA buffers is also
placed into a couple of separate subroutines, for the sake of
cleanliness and consistency.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as952) adjusts the spinlock usage in the root-hub
emulation part of usbcore, to make it match more closely the pattern
used by regular host controller drivers. To wit: The private lock
(usb_hcd_root_hub_lock) is held throughout the important parts, and it
is dropped temporarily without re-enabling interrupts around the call
to usb_hcd_giveback_urb().
A nice side effect is that the code now avoids calling
local_irq_save(), thereby becoming more RT-friendly.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as951) cleans up a few loose ends from earlier patches.
Redundant checks for non-NULL urb->dev are removed, as are checks of
urb->dev->bus (which can never be NULL). Conversely, a check for
non-NULL urb->ep is added to the unlink paths.
A homegrown round-down-to-power-of-2 loop is simplified by using the
ilog2 routine. The comparison in usb_urb_dir_in() is made more
transparent.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as946) eliminates many of the uses of urb->pipe in
usbcore. Unfortunately there will have to be a significant API
change, affecting all USB drivers, before we can remove it entirely.
This patch contents itself with changing only the interface to
usb_buffer_map_sg() and friends: The pipe argument is replaced with a
direction flag. That can be done easily because those routines get
used in only one place.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as945) adds a bit to urb->transfer_flags for recording the
direction of the URB. The bit is set/cleared automatically in
usb_submit_urb() so drivers don't have to worry about it (although as
a result, it isn't valid until the URB has been submitted). Inline
routines are added for easily checking an URB's direction. They
replace calls to usb_pipein in the DMA-mapping parts of hcd.c.
For non-control endpoints, the direction is determined directly from
the endpoint descriptor. However control endpoints are
bi-directional; for them the direction is determined from the
bRequestType byte and the wLength value in the setup packet.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as944) adds an explicit "enabled" field to the
usb_host_endpoint structure and uses it in place of the current
mechanism. This is merely a time-space tradeoff; it makes checking
whether URBs may be submitted to an endpoint simpler. The existing
mechanism is efficient when converting urb->pipe to an endpoint
pointer, but it's not so efficient when urb->ep is used instead.
As a side effect, the procedure for enabling an endpoint is now a
little more complicated. The ad-hoc inline code in usb.c and hub.c
for enabling ep0 is now replaced with calls to usb_enable_endpoint,
which is no longer static.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as943) prepares the way for eliminating urb->pipe by
introducing an endpoint pointer into struct urb. For now urb->ep
is set by usb_submit_urb() from the pipe value; eventually drivers
will set it themselves and we will remove urb->pipe completely.
The patch also adds new inline routines to retrieve an endpoint
descriptor's number and transfer type, essentially as replacements for
usb_pipeendpoint and usb_pipetype.
usb_submit_urb(), usb_hcd_submit_urb(), and usb_hcd_unlink_urb() are
converted to use the new field and new routines. Other parts of
usbcore will be converted in later patches.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as940 renames hcd_data_lock in hcd.c to hcd_urb_list_lock,
which is more descriptive of the lock's job. It also introduces a
convenient inline routine for testing whether a particular USB device
is a root hub.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as939) moves a couple of routine in hcd.c around. The
purpose is to put all the general URB- and endpoint-related routines
(submit, unlink, giveback, and disable) together in one spot.
There are no functional changes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Root hubs can't be resumed if their parent controller device is still
suspended. This patch (as925) adds a check for that condition in
hcd_bus_resume() and prevents it from being treated as a fatal
controller failure.
ehci-hcd is updated to add the corresponding test. Unnecessary
debugging messages are removed from uhci-hcd and dummy-hcd. The
error return code from dummy-hcd is changed to -ESHUTDOWN, the same as
the others. ohci-hcd doesn't need any changes.
Suspend handling in the non-PCI host drivers is somewhat hit-and-miss.
This patch shouldn't have any effect on them.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as922) removes all but one of the remaining vestiges of
dev->power.power_state from usbcore. The only usage left must remain
until the deprecated "power/state" sysfs attribute is gone.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch releases DMA resources if enqueue fails in the HCD.
Linux had this bug ever since we converted from virt_to_bus for 2.4.
It is difficult to hit. A user would need a significant memory pressure
or some other unusual condition.
It was reported to me by IBM. They ran a management application for
RSA II adapters which sent Bulk requests to an Interrupt endpoint.
Submissions got rejected by HCD due to an invalid interval value
and the swiotlb pool became depleted in the matter of hours.
We fixed the invalid interval issue in devio.c separately, but this
seems to be a bug worth fixing as well.
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as916) completes the separation of code paths for suspend
and resume of root hubs as opposed to non-root devices. Root hubs
will be power-managed through their bus_suspend and bus_resume
methods, whereas normal devices will use usb_port_suspend() and
usb_port_resume().
Changes to the hcd_bus_{suspend,resume} routines mostly represent
motion of code that was already present elsewhere. They include:
Adding debugging log messages,
Setting the device state appropriately, and
Adding a resume recovery time delay.
Changes to the port-suspend and port-resume routines in hub.c include:
Removal of checks for root devices (since they will never
be triggered), and
Removal of checks for NULL or invalid device pointers (these
were left over from earlier kernel versions and aren't needed
at all).
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch modifies the USB regular 250ms timer to be "perfectly aligned" to
the second and quarters thereof. This change is there to make sure that if
you have multiple USB ports, the timers for all these ports will fire at the
same time rather than all spread out. All spread out wakes the CPU up from
power saving idle a lot more than needed...
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as912) replaces a couple of calls to flush_workqueue()
with cancel_sync_work() and cancel_rearming_delayed_work(). Using a
more directed approach allows us to avoid some nasty deadlocks. The
prime example occurs when a first-level device (the parent is a root
hub) is removed while at the same time the root hub gets a remote
wakeup request. khubd would try to flush the autosuspend workqueue
while holding the root-hub's lock, and the remote-wakeup workqueue
routine would be waiting to lock the root hub.
The patch also reorganizes the power management portion of
usb_disconnect(), separating it out into its own routine. The
autosuspend workqueue entry is cancelled immediately instead of
waiting for the device's release routine. In addition,
synchronization with the autosuspend thread is carried out even for
root hubs (an oversight in the original code).
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg KH <gregkh@suse.de>
Cc: Mark Lord <lkml@rtr.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I haven't personally run across an oops because of this, but I feel safer
with this fix in place.
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
